«if,» «even if,» «whether,» «unless,» «but for,» «otherwise,» «provided,» «suppose»

[A] even if = even though

Comparar:

• You must go tomorrow if you are ready, y:
• You must go tomorrow even if you aren’t ready.

[B] whether … or = if … or

• You must go tomorrow whether you are ready or not.

[C] unless + verbo afirmativo = if + negación

• Unless you start at one you’ll be late= 

= If you don’t start at once you’ll be late.

• Unless you had a permit you couldn’t get a Job =

= If you hadn’t a permit you couldn’t get a job.

Notar la diferencia entre:

(a) Don’t call ‘me if you need help, y

(b) Don’t call me unless you need help.

En (a) el hablante no va a ayudar incluso en el caso de que se necesite ayuda.

En (b) el hablante va ayudar si se necesita ayuda pero no desea llamadas no urgentes.

unless + he‘d/you‘d like/prefer etc. normalmente reemplaza if he/you wouldn‘t like etc. :

• I’ll ask Tom, unless you’d prefer me to ask/unless you’d rather I asked Bill. 

[D] but for = «if it were not for/if it hadn’t been for»

• My father pays my fees. But for that I wouldn’t be here.
• The car broke down. But for that we would have been in time.

[E] otherwise = «if this doesn’t happen/didn’t happen/hadn’t happened»

• We must be back before midnight; otherwise we’ll be locked out = 

= If we are not back by midnight we’ll be locked out.

– Her father pays her fees; otherwise she wouldn’t be here =

= If her father didn’t pay her fees she wouldn’t be here.

– I used my calculator; otherwise I’d have taken longer =  

= If I hadn’t used my Calculator I’d have taken longer.

[F] En Inglés coloquial or (+ else) puede reemplazar a menudo otherwise:

• We must be early or (else) we won’t get a seat.

[G] provided (that) puede reemplazar a if cuando hay una fuerte idea de limitación o restricción. Se usa principalmente con permisos.

• You can camp here provided you leave no mess.

[H] suppose/supposing … ? = what if …?

• Suppose the plane is late? =

= What if/What will happen if the plane is late?

• Suppose no one had been there? =

= What if no one had been there?

suppose también puede introducir sugerencias:

• Suppose you ask him/Why don’t you ask him?